Bluetooth: Audio: Use generic zephyr_count_bits to count bits

Instead of re-implementing or assuming that POPCOUNT is available
we now use the generic function from Zephyr.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>

Author: Thalley

samples/bluetooth/cap_acceptor/src/cap_acceptor_broadcast.c

@@ -1,7 +1,7 @@
 /** @file
  *  @brief Bluetooth Common Audio Profile (CAP) Acceptor broadcast.
  *
- *  Copyright (c) 2024 Nordic Semiconductor ASA
+ *  Copyright (c) 2024-2025 Nordic Semiconductor ASA
  *
  *  SPDX-License-Identifier: Apache-2.0
  */
@@ -459,7 +459,8 @@ static int bis_sync_req_cb(struct bt_conn *conn,
 
 	LOG_INF("BIS sync request received for %p: 0x%08x", recv_state, bis_sync_req[0]);
 
-	if (new_bis_sync_req != BT_BAP_BIS_SYNC_NO_PREF && POPCOUNT(new_bis_sync_req) > 1U) {
+	if (new_bis_sync_req != BT_BAP_BIS_SYNC_NO_PREF &&
+	    zephyr_count_bits(&new_bis_sync_req, sizeof(new_bis_sync_req)) > 1U) {
 		LOG_WRN("Rejecting BIS sync request for 0x%08X as we do not support that",
 			new_bis_sync_req);
 

subsys/bluetooth/audio/audio.c

@@ -2,6 +2,7 @@
 
 /*
  * Copyright (c) 2022 Codecoup
+ * Copyright (c) 2025 Nordic Semiconductor ASA
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -23,6 +24,7 @@
 #include <zephyr/bluetooth/hci_types.h>
 #include <zephyr/logging/log.h>
 #include <zephyr/sys/check.h>
+#include <zephyr/sys/util.h>
 #include <zephyr/toolchain.h>
 
 #include "audio_internal.h"
@@ -146,18 +148,7 @@ uint8_t bt_audio_get_chan_count(enum bt_audio_location chan_allocation)
 		return 1;
 	}
 
-#ifdef POPCOUNT
-	return POPCOUNT(chan_allocation);
-#else
-	uint8_t cnt = 0U;
-
-	while (chan_allocation != 0U) {
-		cnt += chan_allocation & 1U;
-		chan_allocation >>= 1U;
-	}
-
-	return cnt;
-#endif
+	return zephyr_count_bits(&chan_allocation, sizeof(chan_allocation));
 }
 
 static bool valid_ltv_cb(struct bt_data *data, void *user_data)

subsys/bluetooth/audio/bap_broadcast_sink.c

@@ -1093,22 +1093,6 @@ int bt_bap_broadcast_sink_create(struct bt_le_per_adv_sync *pa_sync, uint32_t br
 	return 0;
 }
 
-static uint8_t bit_count(uint32_t bitfield)
-{
-#ifdef POPCOUNT
-	return POPCOUNT(bitfield);
-#else
-	uint8_t cnt = 0U;
-
-	while (bitfield != 0U) {
-		cnt += bitfield & 1U;
-		bitfield >>= 1U;
-	}
-
-	return cnt;
-#endif
-}
-
 struct sync_base_info_data {
 	struct bt_audio_codec_cfg codec_cfgs[CONFIG_BT_BAP_BROADCAST_SNK_STREAM_COUNT];
 	struct bt_audio_codec_cfg *subgroup_codec_cfg;
@@ -1293,7 +1277,7 @@ int bt_bap_broadcast_sink_sync(struct bt_bap_broadcast_sink *sink, uint32_t inde
 	}
 
 	/* Validate that number of bits set is within supported range */
-	bis_count = bit_count(indexes_bitfield);
+	bis_count = zephyr_count_bits(&indexes_bitfield, sizeof(indexes_bitfield));
 	if (bis_count > CONFIG_BT_BAP_BROADCAST_SNK_STREAM_COUNT) {
 		LOG_DBG("Cannot sync to more than %d streams (%u was requested)",
 			CONFIG_BT_BAP_BROADCAST_SNK_STREAM_COUNT, bis_count);

tests/bsim/bluetooth/audio/src/bap_broadcast_sink_test.c

@@ -801,7 +801,7 @@ static void test_broadcast_sync(const uint8_t broadcast_code[BT_ISO_BROADCAST_CO
 		return;
 	}
 
-	stream_sync_cnt = POPCOUNT(bis_index_bitfield);
+	stream_sync_cnt = zephyr_count_bits(&bis_index_bitfield, sizeof(bis_index_bitfield));
 }
 
 static void test_broadcast_sync_inval(void)